Skip to content
Blood Test Tracker

Sesame Seed IgE

Shows whether your immune system has made IgE antibodies to sesame. This is called sensitization and doesn't always mean a sesame allergy.

AI-verified against cited sources. Awaiting expert reviewAlso called f10, F010LOINC 6242-2

Check your result

Sex (optional)

Type your result to see where it falls.

Nothing you type here leaves your browser.

What it is

Sesame seeds come from the Sesamum indicum plant and turn up in breads, tahini, halva and many other foods, as well as in oils. This test measures IgE, the antibody type linked to allergic reactions, that your body has made against sesame. Sensitization means your body has made IgE antibodies to a substance. It does not always mean you are allergic. In the US, sesame became the ninth major food allergen that packaged foods must name on the label on January 1, 2023.

Why it matters

Sesame allergy can cause reactions that range from hives and stomach upset to a serious reaction called anaphylaxis. In a large US survey, about 24% to 37% of people with a convincing sesame allergy had a severe reaction at some point, depending on how severity was defined. A blood IgE test for sesame is not a dependable guide on its own. Many people who test positive do not react when they eat sesame, and a negative result doesn't fully rule out an allergy. Your history of reactions matters most, and an allergy specialist may use a skin test or a supervised food challenge to settle the question.

If it’s high

A result above your lab's usual range means your body has made IgE antibodies to sesame. It is more likely to match a true sesame allergy if you have had symptoms soon after eating sesame. The number alone can't tell how strong a reaction would be, and no blood test can predict how severe a future reaction will be. In studies that used food challenges, sesame IgE tests were poor at separating people who react from people who don't, so a skin test or a supervised food challenge may be needed to settle the question.

Common causes

  • A true sesame allergy, with symptoms soon after eating sesame
  • Sensitization without symptoms, which is common with food IgE tests
  • Peanut or tree nut allergy, which often occurs alongside sesame sensitization and can raise the sesame result
  • Cross-reaction with proteins in peanut, tree nuts and some other seeds, such as poppy seed
  • A weak result of 0.10 to 0.34 kU/L, which labs treat as uncertain

What can help

  • If you have had symptoms after eating sesame, talk with your clinician before eating it again
  • Ask whether an allergy specialist could do a skin test or a sesame component test (Ses i 1), or arrange a supervised food challenge
  • Ask for a written plan for what to do if you have a reaction
  • Ask how to read food labels, since sesame must now be named on packaged foods in the US

Usual ranges

What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.

For adults: 0–0.09 kU/L. Source: Labcorp, ARUP Laboratories, Quest Diagnostics, Thermo Fisher Scientific (Phadia), NIAID / Journal of Allergy and Clinical Immunology, Journal of Asthma and Allergy, JAMA Network Open, Journal of Allergy and Clinical Immunology, U.S. Food and Drug Administration, MedlinePlus (National Library of Medicine).

ImmunoCAP class scale as printed by Quest and ARUP (labs differ on which class an exact edge value falls in)

  • Class 0: absent or undetectablebelow 0.1 kU/L
  • Class 0/1: very low level, relevance uncertain0.1 to under 0.35 kU/L
  • Class 1: low level0.35 to under 0.7 kU/L
  • Class 2: moderate level0.7 to under 3.5 kU/L
  • Class 3: high level3.5 to under 17.5 kU/L
  • Class 4: very high level17.5 to under 50 kU/L
  • Class 5: very high level50 to under 100.01 kU/L
  • Class 6: very high level100.01 and above kU/L

Labcorp class scale (ImmunoCAP, as printed on Labcorp reports)

  • Class 0: negativebelow 0.1 kU/L
  • Class 0/I: equivocal or low0.1 to under 0.32 kU/L
  • Class I: low0.32 to under 0.56 kU/L
  • Class II: moderate0.56 to under 1.41 kU/L
  • Class III: high1.41 to under 3.91 kU/L
  • Class IV: very high3.91 to under 19.01 kU/L
  • Class V: very high19.01 to under 100.01 kU/L
  • Class VI: very high100.01 and above kU/L

What can affect your result

  • Peanut and tree nut allergy: sesame IgE is often present and can be high even without sesame reactions
  • Test type: in some studies a skin prick test predicted sesame allergy better than the blood IgE test
  • Age and time: most people keep a sesame allergy, but some outgrow it (roughly 20% to 30% in reports), and IgE can fall as that happens
  • Lab method: results from different labs or assay systems may not be comparable
  • Sesame IgE can read unexpectedly high in people with peanut allergy who have no reaction to sesame (reported up to about 5.5 kUA/L in one small group), so a high number alone can mislead.
  • Results from different labs and test brands are not directly comparable, so compare results from the same lab and method (NIAID 2010).
  • Labs may reject samples that are hemolyzed (red cells broken), jaundiced (icteric) or lipemic (very fatty). ARUP lists all three as unacceptable.
  • MedlinePlus notes that some medicines, such as antihistamines, may matter before an allergy blood test. Tell your clinician about everything you take and ask them what applies to you.

Antibody levels usually change slowly, over months to years.

When to talk to a clinician

Call your local emergency number if, soon after eating sesame, you have trouble breathing, throat tightness, swelling of the lips or tongue, repeated vomiting, dizziness or fainting. See a clinician soon if you get hives, itching or stomach upset after eating sesame.

Questions you could ask

  • How should I read this result if I've never had a reaction to sesame?
  • Does this result fit the symptoms I've had after eating sesame?
  • Should I see an allergy specialist, and would a skin test or a sesame component test help?
  • Does my peanut or tree nut allergy, if I have one, change how to read this result?
  • Is a supervised food challenge appropriate for me?
  • What should my plan be if I have a reaction?

Questions people ask

My sesame result is high but I eat sesame without trouble. What does that mean?

Sensitization is common and doesn't always cause symptoms. Sesame IgE can also read high in people with peanut allergy who tolerate sesame. A positive blood test alone doesn't confirm a sesame allergy. Talk with your clinician about whether more testing is needed before changing what you eat.

Can I have a negative result and still be allergic?

It's uncommon, but yes. Case reports describe sesame allergy with negative blood and skin tests. If your history strongly suggests a reaction, your clinician may suggest a supervised food challenge before you eat sesame again.

Do food labels list sesame?

In the US, sesame became the ninth major food allergen on January 1, 2023, so packaged foods must now name it like the other major allergens. Canada, Europe, Australia and New Zealand also treat sesame as a priority allergen for labeling.

Show the science and sources

Units

  • 1 kU/L = 1 kU/L
  • 1 kU/L = 1 UA/mL

For clinicians and researchers

ImmunoCAP f10 is a fluorescent enzyme immunoassay for IgE to a sesame (Sesamum indicum) seed extract. WHO/IUIS lists seven sesame allergens: the 2S albumins Ses i 1 and Ses i 2, the 7S vicilin Ses i 3, the oleosins Ses i 4 and Ses i 5, and the 11S globulins Ses i 6 and Ses i 7. Several are related to peanut allergens (Ses i 1 to Ara h 2, 6 and 7; Ses i 3 to Ara h 1; Ses i 6 to Ara h 3), which can contribute to positive extract tests in peanut-allergic people. Ses i 1 IgE is available as a separate component test (see the catalog's Ses i 1 marker); Thermo Fisher notes it outperformed skin testing in one study. A 2017 systematic review found the diagnostic capacity of serum sesame IgE poor, especially in challenge-confirmed cohorts, with several studies unable to calculate a 95% positive predictive value, one study finding a 7 kUA/L cutoff gave 71% sensitivity and 90% specificity, and case reports of sesame allergy with negative skin and blood tests, possibly from isolated oleosin allergy. The double-blind placebo-controlled food challenge remains the reference standard. Co-allergy is common: the Pronuts challenge study found about 61% of children with a confirmed nut or sesame allergy had coexisting allergy to another of these foods. Sesame allergy resolves in roughly 20% to 30% of patients (Thermo Fisher; the 2017 review cites 20% after about 6.7 years). In a US survey (n=78,851), 0.23% of the population met criteria for convincing IgE-mediated sesame allergy. Under the FASTER Act, sesame became a US major food allergen on January 1, 2023.

LOINC 6242-2 (primary), 112093-0. Specimen: serum.

Sources

  1. F010-IgE Sesame Seed (test 602485), Labcorp
  2. Sample patient report: F010-IgE Sesame Seed (test 602485), Labcorp
  3. Allergen, Food, Sesame Seed (test 0099698), ARUP Laboratories
  4. ImmunoCAP Specific IgE Blood Test: Allergy Test List (interpretation table and test codes), Quest Diagnostics (2017)
  5. Your quick guide to using ImmunoCAP Specific IgE testing, Thermo Fisher Scientific (Phadia)
  6. Allergen Encyclopedia: f10 Sesame seed, Thermo Fisher Scientific (Phadia)
  7. Guidelines for the Diagnosis and Management of Food Allergy in the United States: Report of the NIAID-Sponsored Expert Panel, NIAID / Journal of Allergy and Clinical Immunology (2010)
  8. Sesame allergy: current perspectives, Journal of Asthma and Allergy (2017)
  9. Prevalence and Severity of Sesame Allergy in the United States, JAMA Network Open (2019)
  10. Defining challenge-proven coexistent nut and sesame seed allergy: A prospective multicenter European study, Journal of Allergy and Clinical Immunology (2020)
  11. Food Allergies, U.S. Food and Drug Administration
  12. Prevalence of allergic sensitization in the United States: results from the National Health and Nutrition Examination Survey (NHANES) 2005-2006, Journal of Allergy and Clinical Immunology (2014)
  13. Allergy Blood Test, MedlinePlus (National Library of Medicine)

AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.

Related markers